Pokémon Red and Blue

Game Freak built the game around a cable. The cartridge was released in two versions, some creatures are found only in one of them, and certain evolutions happen only at the moment of a trade. So the full list can't be completed alone no matter how hard you try: you need a second person with a second console and a wire between them. The same cable is used for battles, so the link device becomes a condition for completing the game.

Inside, it's a turn-based RPG with frugal arithmetic. Every creature has a type, the types are linked by a table of strengths and weaknesses, and building a team comes down to covering that table. An opponent is weakened and caught, so a fight becomes a calculation: hit hard enough, but not to the death. The Game Boy screen is monochrome, the sound is simple, the save lives in the cartridge itself, and all this modesty serves the idea. The collection belongs to the owner of the cartridge and travels with it to wherever there is someone to trade with, which means the game leaves the console and goes out into the schoolyard.